Week 1 - Personalized nutrition & PKU

Traditional dietary guidelines provide recommendations based on age, gender, broad health considerations. What is the difference with personalized nutrition?

Personalized nutrition considers genetic, metabolic, behavioral, lifestyle factors.

Why do individuals respond to food differently?

• Genetic variation

• Gut microbiota composition

• Metabolic differences

• Eating habits

• Food preferences

• Personal goals

• Culture

What are the three levels of personalized nutrition?

1. Conventional nutrition

2. Individualized nutrition (Phenotype-based)

3. Nutrigenomics (Genetics-based)

what is conventional nutrition?

• Broadest level, applies to the general population

• General dietary guidelines (NRVs, RDI) for different ages, genders

What is individualized nutrition (phenotype-based)?

• Analyzes anthropometry (BMI, body composition)

• physical activity level, biochemical markers, metabolic profiling, etc.

What is Genotype-Directed nutrition (nutrigenetics)>

Considers genetic variants that influence:

• nutrient metabolism

• food sensitivities

• disease risks

What is Phenylketonuria (PKU)?

A genetic disorder that results in an inability to metabolize phenylalanine.

What is phenylalanine?

An essential amino acid found in many protein-containing foods (meat, dairy, etc)

what is the cause of PKU

• Mutation on chromosome 12 on the PAH gene

• Leads to a deficiency in phenylalanine hydroxylase (PAH)

• Phenyalanine cannot be converted to tyrosine

Effect of phenylalanine build up?

• Brain damage (seizures, etc.)

• Harmful phenylketones are produced

PKU treatment?

• Avoid high-protein foods

• Drink special formula that contains nutrients without Phenylalanine

What is the diagnosis of PKU in babies?

Small sample of blood is taken from baby’s heel within the first 48 hours, and tested for elevated levels of Phe

What is the challenge of the PKU diagnosis?

It is difficult to pinpoint the exact mutation causing PKU, as there are over 600 different mutations of the PAH gene.